Banking and escapement apparatus for electric typewriters or the like



y 1962 H. LAMBERT ETAL 3,045,798

BANKING AND ESCAPEMENT APPARATUS FOR ELECTRIC TYPEWRITERS OR THE LIKE Filed July 15, 1960 2 Sheets-Sheet 1 Fig.1

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INVENTO S IAQSEYFL. PLIgBERT BY I 3? t M I 1 ATTORNE y 1962 H. LAMBERT ETAL 3,045,798

BANKING AND ESCAPEMENT APPARATUS FOR ELECTRIC TYPE-WRITERS OR THE LIKE 2 Sheets-Sheet 2 Filed July 15, 1960 ll mm INVENTORS HARRY L. LAMBERT UL AGE v 3,045,798 BANKING AND ESQAPEMENT APPARATUS Fill; ELECTRIC TYPEWRITIERS QR THE LIKE Harry L. Lambert, West Hartford, and Paul F. Page,

Newington, Conn, assignors to Royal McBee Corporation, Port Chester, N.Y., a corporation of New York Filed July 15, 1960, Ser. No. 43,176 16 Claims. (Cl. 197-34) This invention relates to an improved banking and escapement apparatus for electric typewriters or the like, and more particularly relates to a novel arrangement for reducing noise during a carriage return operation and for insuring an even left hand margin on the record sheet when the carriage of a typewriter is either manually or power operated through a return movement.

During the operation of an electric typewriter, the typist normally uses the power operated linkage to effect carriage return movements. At the end of the carriage return travel the power drive clutch is disengaged and the escapement mechanism is conditioned to take over the letter feed control of the carriage in response to the approach and/or arrival of the carriage to the banked or right hand position. Occasionally the typist will manually displace the carriage to its banked or right hand position and here a different set of conditions can occur at or near the end of this banking movement. In either of these cases it is necessary that an even left hand margin be maintained for the typed material. In those electric typewriters having escapement mechanisms of the general type hereinafter disclosed it is desirable to provide a means for insuring that the escapement mechanism is properly conditioned for proper margin control when the carriage is manually as well as power operated through a return stroke.

During the carriage return movements of most typewriters a ratcheting type noise is made due to the operation of the one-way coupling between the escapement wheel and the carriage. This noise, although perhaps not seriously objectionable, adds to the average noise level of the general machine operation and hence is best avoided if possible.

One object of the present invention is to provide an improved system fOr the manual and/ or power banking of the carriage of an electric typewriter.

Another object of the invention is to provide a novel apparatus for reducing the noise attendant upon a carriage return operation.

Another object of the invention is to provide an improved carriage escapement and banking arrangement for a typewriter whereby an even left hand margin for the typed material is assured.

A further object of the invention is to provide an escapement mechanism having a plurality of movable stops all of which are moved to and retained in set positions during power operated carriage return movements, and predetermined ones of which are displaced to inoperative positions at the end of the carriage return movement.

Still another object of the invention is to provide an escapcment mechanism having a, plurality of movable stops, a small group of which are always in inoperative positions during a manual carriage return operation, and predetermined ones of which group are displaced to op erative positions in response to the completion of said carriage return operation.

Still another object of the invention is to provide an escapement wheel that operatively supports a series of movable stops arranged in circular array, some of said stops being shaped difierently than the remaining stops so that all of the stops effectively define a relatively fine toothed escapement wheel while the consecutive differ-- 345J93 Patented July 24, 1962 ently shaped stops effectively define a coarse toothed cscapement wheel wherein the effective distance between the successive differently shaped stops is an even multiple of the eifective distance between each of the consecutive stops of said fine toothed wheel.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numer-als designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a plan view taken is partial section and shows the principal parts of the instant banking and escapement mechanisms.

FIGURE 2 is a front elevational view of the apparatus of FIGURE 1.

FIGURE 3 is a perspective view showing the normal condition of the principal parts of the banking mechanism.

FIGURE 4 is a front elevational view showing cam means for displacing the movable stops to set positions.

FIGURE 5 is a plan view illustrating an active condition of the FIGURE 1 apparatus during a power operated carriage return stroke.

FIGURE 6 is a fragmentary plan view illustrating another active condition for the apparatus of FIGURE 1 during a manually operated carriage return stroke.

Except as otherwise hereinafter described the escapement mechanism illustrated in FIGURES 1 and '2 is similar in construction and operation to that shown and described in copending application Serial No. 834,597, filed August 18, 1959, now Patent No. 3,018,870, for Proportional Spacing Mechanism. By way of general review this mechanism comprises a wheel 10 fixed to a shaft 11 that is rotatably mounted on the machine frame '12. Fixed to shaft 111 is -a pinion 13 which meshes with the rack 14 secured to the typewriter carriage 15. Disposed in circular array about the periphery of wheel 10 is a plurality of radially oriented stops 16 which are movable in an axial direction to set and unset positions. In the set positions the respective forward ends of said stops are adapted to engage the shoulder 17 formed on the end of a normally stationary abutment member 20 that is pivotally mounted on frame 12. This engaging action serves to hold the carriage against letter feed movement under the action of the usual spring barrel drive arrangement. When the stops 16 are in their respective unset positions their said forward ends are substantially flush with the adjacent face of wheel It) and are free to swing past the shoulder 1'! of abutment member Ztl so as to thereby permit letter feed movement of the carriage.

A cam plate 21, FIGURES l and 4, formed With a pair of wedge shaped cams 22 and 23 is mounted adjacent the lower rearward face of wheel 10 so as to progressively cam the stops 16 to set positions in response to the rotation of said wheel in either direction. A plurality of selectively operable stop setting fingers 2d, 25, 26 and 27 are provided so that upon selective operation thereof different numbers of said set stops just to the left of abutment member 20 may be successively displaced to unset positions to permit the carriage to intermittently partake of letter spacing movements of varying lengths and to thereby accommodate the different widths of the characters typed. The abutment member 20 is provided with a tapered undercut cam surface 28 which will cam all set stops 16 to unset positions as the latter move in a clockwise direction, FIGURE 2, past said abutment member during any movement of the carriage in a return direction and while the abutment member is in its normal FIGURE 1 position. A second abutment member 30 is provided for use when expanded letter spacing of the carriage is desired. The abutment members and are pivotally mounted on the machine frame by means of a stud 31 and each is adapted to be swung in a counterclockwise direction away from their normal superimposed FIGURE 1 positions by the respective upper and lower toggle linkages 32 and 33. The toggle linkages 32 and 33 are spring biased to their normal locked FIGURE 1 positions as determined by the frame stud 34. As noted above the construction and operation of this apparatus is more or less .similar to that shown in said copending application and if further details are necessary or desired specific reference to said application may be made.

The above described apparatus is modified as follows. At the outer end of the lower toggle linkage 33 there is fixed a pin to which is articulately connected a link 41 that is pivotally connected to one of the standard parts 42 of the power operated carriage return control linkage of the typewriter. The pin 40 extends upwardly to a point adjacent the left edge, FIGURE 1, of the member 43 of the upper toggle linkage 32 so that when said power operated carriage return linkage is actuated both abutment members are pivoted away from their normal operative FIGURE 1 positions. The upper toggle linkage 32 may be operated independently of the lower toggle linkage by any suitable manually operable means such as that illustrated in said copending application.

A stop cam blade 45, FIGURES l3, is pivotally mounted on said stud 31 and has a free end 46 which normally extends laterally across the lower front region of the escapement wheel 10. The righthand end 47, FIG- URE 1, of blade is formed with a bent over ear 48 to which is fastened a spring 49 that is anchored on the frame stud 50. Said car 48 cooperates with the camming edge 51 of the forwardly extending arm 52 of a bell crank 53 that is pivotally mounted on the machine frame by means of stud 54, Bell crank 53 is articulately connected by means of a link 55 to the usual carriage return paddle arm 56 that is pivotally mounted as at 57 on the frame center post 60 of the typewriter. The linkage 45-56 just described is normally maintained in the illustrated condition by means of said spring 49. The free end 61 of the elongated laterally extending arm 62 of the bell crank 53 is normally disposed adjacent the rearward end 63 of a plunger 64, FIGURES 1 and 3, that is axially slidably mounted in the machine frame. The plunger 64 is axially biased rearwardly by a compression spring 65 and has secured to its forward end a stop setting arcuately shaped cam blade 66, FIGURES 3 and 4, having a forward arcuate edge 67 and two tapered side camming surfaces 70 and 71. The arcuate edge 67 lies just to the rear to those three stops 16a, FIGURES 2 and 4, which are just to the right of the tip or point 72, FIGURES l and 3, of the wedge shaped cam 22. As will be apparent when the plunger 64 is displaced forwardly against the action of spring 65 any unset stops which are located in front of cam blade 66 will be displaced to set positions. The upper end 73 of the carriage return paddle arm 56 lies in the path of travel of the usual left hand margin stop 74 that is adjustably secured to the typewriter carriage 15 in the usual manner.

Every third stop 168, FIGURE 2, on the escapement Wheel 10 is radially shorter than the intermediate longer stops 16L and has a different effective path of travel than that of the latter. All the stops 16 effectively define a relative fine toothed escapement wheel, while the group of shorter stops 16S effectively define a coarse toothed escapement Wheel wherein the coarsely spaced teeth correspond to the desired banked and/ or tabulated positions for the carriage. The free end 46 of the stop cam blade 45 is provided with a stop displacing edge 75, FIGURE 3, and adjacent inclined stop camming surfaces 76 and 77. The blade end 46 is normally disposed a slight distanee away from the front face of escapement wheel 10 and away from any of the stops 16 as is illustrated in FIGURE 1. When the blade end is displaced towards the wheel 10 to a position overlying the abutment member 20, as illustrated in FIGURE 6, the stop displacing edge 75 will move into the circular path of travel of the radially inner portions of the said long stops 16L; thi path of travel being radially inward of that for the said short stops 165.

The operation of the above described apparatus is as follows: the normal condition of the parts is shown in FIGURES 1-3. During normal typing operations the stop setting finger 24 is repeatedly actuated during each typing stroke. One or more of the three additional fingers 25-27 may be simultaneously operated so as to thereby displace to unset positions a varying number of said stops 16 and thus control the variable length of the successive letter feed movements of the carriage occurring during the sequential typing of characters having varying widths. When a power operated carriage return operation is initiated the said standard part 42, FIGURE 1, of the carriage return linkage will be displaced and held to the right in the usual manner and will, through link 41, swing both abutment members 20 and 30 in a counter clockwise direction out of the operative circular path of travel of the stops 16 as illustrated in FIGURE 5. During the carriage return movement the carriage rack 14 and the wheel pinion 13 remain in engagement and hence the wheel 10 will be driven in a clockwise direction, FIGURE 2. During this wheel rotation all of the stops 16 will be cammed to their set positions by the cam 22 and/ or 23 and in that both the abutment members 20 and 30 as well as the blade 45 are out of the path of travel of stops 16, said stops will remain in said set positions during the carriage return movement. As soon as the left margin stop 74 strikes and displaces the paddle arm 56 in a clockwise direction to an extent permitted by the center post 69, two simultaneous resultant actions occur; first the part 42 is permitted to assume its normal FIGURE 1 position thereby permitting the abutment members 20 and 30 to be spring restored to their normal FIGURE 1 positions by springs 86 and 81. This action serves to displace two of the set stops to unset positions by reason of the rearward face 80, FIGURE 1, of the abutment member 20 moving into the path of travel of said stops 16. Secondly, movement of paddle arm 56 will, through link 55, rotate bell crank 53 in a counterclockwise direction thereby displacing the camming edge 51 so as to swing the blade 45 in clockwise direction, FIGURE 1, into the operative path of travel of stops 16L. Both of these two actions are illustrated in FIGURE 6. When the carriage return movement is thus arrested the clockwise rotation of wheel 10 is also arrested and the simultaneous swinging movement of blade 45 will cause the stop engaging edge 75 of the latter to engage and displace to unset position the next stop just to the left of abutment shoulder 17 if this next stop of the now rotationally arrested wheel happens to be a long stop 16L as illustrated in FIGURE 6. When the return movement of carriage is fully arrested the spring barrel drive arrangement will immediately urge the carriage in a letter feed direction to an extent permitted by that amount of counter clockwise movement of wheel 10 which is necessary to swing the first short stop 168 into operative engagement with the abutment member 20. When blade 45 is swung to the FIGURE 6 position the long stops 16L are cammed to unset positions and, as may be readily seen, the carriage banking operation will always be completed with one of the short stops 16S in operative engagement with said abutment member 20. This action will insure that the carriage is always returned to a predetermined banked position and that the left hand margin of the typed material is straight and even. When the banking operation is completed the blade 45 will be permitted to swing back to its normal FIGURE 1 position under the action of spring 49.

The above described operation involves a power operated return movement of the carriage. When, as occasionally occurs, a manually operated carriage return movement is effected the power linkage parts 42 etc. will not be actuated and hence the abutment members 20 and 30 will remain in their normal FIGURE 1 positions during the carriage return movement. Under these conditions the cams 22 and/or 23 will again progressively displace the stops 16 to set positions in response to the clockwise return rotation of wheel 10, however here the tapered undercut camming surface 28 on abutment member 26) will progressively displace said set stops to unset positions. It will be noted that as the stops 16 are here being alternately displaced back and forth to set and unset positions during the manual carriage return operation, at any given time those five stops which are located between the shoulder 17 of abutment member 20 and the point 72 of cam 22 will always be in unset positions. Thus when any manual carriage return movement is completed and the spring barrel drive again urges the carriage in a letter feed direction the carriage, unless otherwise prevented, would not be arrested until the wheel had r0- tated in a counterclockwise direction by an amount sufficient to let the sixth stop 16 to the left of the abutment shoulder 17 swing into engagement with said shoulder 17, said sixth stop being the first next stop which was then disposed in the set position. This amount of back drop of the carriage after a carriage return movement would be excessive and hence the above described cam means 66, etc., is made operative in the following manner so as to avoid such excessive back drop. At the end of the manually operated carriage return movement the said rotational displacement of the paddle arm 56 not only serves to swing the blade 45 into the path of travel of the stops as described above and as illustrated in FIGURE 6, but also,

plunger 64 in a forward direction against the action of spring 65, as shown in FIGURE 6, so that the arcuate cam edge 67 displaces the three adjacent stops 16a of the now rotationally arrested wheel 10 to set positions. Here then the carriage back drop movement will continue only until the short one 168 of these three now set stops 16a swings into operative engagement with said abutment shoulder 17. Thus after a manually operated carriage return movement the banking operation will always be completed by having one of the short stops 165 in operative engagement with said abutment shoulder 17 thereby assuring the continued maintenance of an even straight left hand margin for the typed material. After completion of any banking operation the blade 45 and the cam plunger 64 are permitted to be moved to their normal FIGURE 1 positions by means of springs 49 and 65 respectively.

It will be noted that cam plunger 64 is axially displaced during a power as well as a manually operated carriage return operation; however in the power operated case such plunger displacement is functionally redundant in that under the existent conditions all of the stops 16 will at that time be in set positions as described above. It will also be noted that when blade 45 and plunger 64 are moved towards the stops 16 the wheel 10 will usually have been just arrested by the cooperative action of the margin stop 74 and the center post 60. If however there is any small amount of residual rotation of the wheel 10 occurring when said blade and plunger are operatively displaced as described such will be functionally accommodated by the respective tapered camrning surfaces 70, 71 and 76, 77 formed on said cam blade 66 and said blade 45 respectively.

During a power operated carriage return movement the abutment members 2t) and 30 are swung to inoperative positions and once all the stops 16 have been cammed to set positions by the first revolution of the wheel 10, the wheel then becomes a free running element during the rest of the carriage return travel. Thus the carriage return movement is not accompanied by the usual ratcheting action and its attendant noise, and hence such movement may here be executed in a smooth and relatively quiet manner.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration only and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

The invention claimed is:

1. In a typewriter having a frame and a carriage movably mounted on said frame, an escapement mechanism for controlling the letter feed movements of said carriage, said escapement mechanism comprising a wheel rotatably mounted on said frame and interconnected with said carriage, a normally stationary abutment member mounted on said frame and adjacent said wheel, and a series of stops each movably mounted on said wheel and being movable to set and unset positions with respect to said abutment member, and means to move said stops between set and unset positions during a banking operation, one group of said stops in said series having an effective path of travel which is diflerent than that for the remaining stops, said wheel and all of said stops effectively defining an escapement wheel having a large number of relatively finely spaced teeth and said wheel and said group of said stops eifectively defining an escapement wheel having a small number of relatively coarsely spaced teeth that correspond to the banking and tabular positions possible for the said carriage.

2. Apparatus as defined by claim 1 additionally comprising linkage means operable in response to a carriage banking operation, and means operated by said linkage means for permitting one of only said group of stops to cooperate with said normally stationary abutment member after completion of said banking operation so as to insure that said carriage is then maintained in a predetermined banked position by said escapement mechanism.

3. Apparatus as defined by claim 2 additionally comprising power means for displacing said carriage through a return movement, means responsive to the operation of said power means for moving said abutment member away from the operative path of travel of said stops, and means for moving said abutment member back to its normal operative position upon completion of the carriage banking operation while several of said remaining stops are being displaced from set to unset positions by the means operated by said linkage means.

4. Apparatus as defined by claim 2 wherein said abutment member remains in its normal operative position during a manually operated carriage return movement and wherein said last mentioned means includes an element so located with respect to said abutment member as to be etfective upon operation of said means to displace to set position a predetermined number of consecutive stops located a predetermined distance from said abutment member.

5. Apparatus as defined by claim 2 wherein said means operated by said linkage means comprises a stop camming blade pivotally mounted on said frame and adapted to displace some of said remaining stops to unset positions upon completion of said carriage return movement so that only a stop adjacent to said abut-ment member in said group of stops remains in set position to cooperate with said abutment member to maintain said carriage in the proper banked position.

6. In a typewriter having a frame, a carriage movably mounted on said frame, an escapement mechanism for controlling the letter feed movement of said carriage, and means for effecting a return movement of said carriage; said escapement mechanism comprising a wheel rotatably mounted on said frame and geared to said carriage, a series of stops mounted on said wheel, a normally stationary abutment member mounted on said frame, said stops each being movable to a set position so as to cooperate with said abutment member and thereby prevent letter feed movement of said carriage and to an unset position so as to be able to by-pass said member and thereby permit letter feed movement of said carriage, means responsive to the operation of said carriage return means for moving said abutment member out of the operative path of travel of said stops and banking control means responsive to the completion of the carriage return movement for effecting restoration of said abutment member to its normal operative position in the path of movement of the set stops and for displacing only predetermined ones of said stops.

7. Apparatus as defined by claim 2; additionally comprising means operable by said linkage means for displacing a predetermined number of those stops located immediately adjacent said abutment member to set positions, only one of said predetermined number of stops defining one of the said coarsely spaced wheel teeth.

8. Apparatus as defined by claim 6 wherein the banking control means includes an element that moves at least one of said stops to an unset position.

9. Apparatus as defined by claim 8 wherein the banking control means includes an element that moves at least one of said stops to a set position.

10. Apparatus as defined by claim 6 wherein a group of said stops are shaped differently than the remaining stops and wherein said banking control means renders effective one stop in only said group to cooperate with said abutment member after completion of a carriage return movement.

11. Apparatus as defined by claim 10 wherein said group of stops is defined by every third one of said series.

12. Apparatus as defined by claim 11 wherein every stop in said group corresponds to one of the banked positions possible for the typewriter carriage.

13. In a typewriter having a frame, a carriage movably mounted on said frame, said carriage being adapted to be manually and power operated through a return movement, an escapement mechanism for controlling the letter feed movement of said carriage, said escapement mechanism comprising a wheel rotatably mounted on said frame and geared to said carriage, a normally stationary abutment member mounted on said frame, and a series of stops mounted on said wheel for movement to set positions for cooperation with said abutment member so as to prevent letter feeding movement of said carriage and to unset positions so as to be able to by-pass said member and thereby permit letter feeding movement of said carriage, the operative path of travel of a group of said stops being different than that for the remaining stops in said series, means for moving said abutment member out of the operative path of travel of said stops during a power operated return movement of said carriage, means to return said abutment member into said path upon completion ofa carriage return movement, means for camming said stops to set positions during a carriage return movement, a first stop camming means operable to displace some of said remaining stops from set positions to unset position at the end of a power operated return movement of said carriage, and a second stop camming means operable to displace a predetermined number of said stops from unset to set positions at the end of a manually operated return movement of said carriage, the position of said carriage after any return movement always being determined by engagement of one of said group of stops with said abutment member.

14. In a typewriter having a frame, a carriage movably mounted on said frame, an escapement mechanism for controlling the letter feed movement of said carriage, and means for effecting a return movement of said carriage, said escapement mechanism comprising a wheel rotatably mounted on said frame and geared to said carriage, a series of stops mounted on said wheel, a normally stationary abutment member mounted on said frame, said stops each being movable to a set position so as to cooperate with said abutment member and thereby prevent letter feed movement of said carriage and to an unset position so as to be able to by-pass said member and thereby permit letter feed movement of said carriage, means responsive to the operation of said carriage return means for moving said abutment member out of the operative path of travel of said stops, means for moving all of said stops to set position during the initial portion of a carriage return movement, all of said stops remaining in said set positions during most of said return movement, and banking control means operative during the carriage banking operation for displacing a few of many predetermined ones of said set stops to unset positions and leaving one of the remaining group of said stops in set position so as to be capable of operatively engaging said abutment member thus insuring a predetermined uniform banked position for the typewriter carriage.

15. Apparatus as defined by claim 14 wherein a predetermined number of all of said stops that are in set positions during most of said carriage return movement are progressively moved to unset positions by a cam on said abutment member when said carriage return movement is effected manually, and means responsive to completion of the manual carriage return movement for moving at least some of said predetermined number of stops in unset positions to set positions, said banking control means being thereafter operative to move to unset position at least one of the stops moved to set position by the last mentioned means.

16. Apparatus as defined by claim 14 wherein the stops in said group are uniformly distributed and have a shape different from that of the said predetermined stops so that the operation of said banking control means is ineffective to displace any of said group of stops to unset position during a carriage banking operation.

References Cited in the file of this patent UNITED STATES PATENTS 1,286,186 Miller Nov. 26, 1918 2,797,789 Yaeger July 2, 1957 2,808,143 Khalil Oct. 1, 1957 FOREIGN PATENTS 529,261 Italy June 21, 1955 

